Here you can find the source of buildTreeSet(Collection
public static <T> TreeSet<T> buildTreeSet(Collection<T> elements)
//package com.java2s; /**//from www.j a va2 s . c om * Copyright (C) 2008 Atlassian * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.Arrays; import java.util.Collection; import java.util.TreeSet; public class Main { public static <T> TreeSet<T> buildTreeSet(T... elements) { return new TreeSet<T>(Arrays.asList(elements)); } public static <T> TreeSet<T> buildTreeSet() { return new TreeSet<T>(); } public static <T> TreeSet<T> buildTreeSet(Collection<T> elements) { return new TreeSet<T>(elements); } }